The invention relates to a method of unwinding an elongate product from a storage device, on which the product is stored with a large number of turns.
EP 0 182 981 discloses an apparatus in which an optical waveguide is hauled off a driven, rotating plate over a pivotably suspended lever and a following, freely rotatable deflection roller. In this case, the deflection roller is located in a plane perpendicular to the face of the plate. Its running face runs tang tangentially to the windings of the optical waveguide on the plate. At its end adjacent to the plate, the lever has an eye to guide the optical waveguide. Because of its ability to pivot parallel to the haul-off plane of the optical waveguide, it is able to follow the wandering of the optical waveguide, within certain limits, as said waveguide changes from one winding path to the next. As a result of the lever pivoting outward, a transmitter, such as a potentiometer, is actuated and influences the rotational speed of the plate in such a way that the lever returns to its central position. Satisfactory unwinding or hauling-off of the optical waveguide stored in this way from the plate for subsequent further processing steps can be made more difficult in practice. In particular, there is the danger that the optical waveguide hauled off the plate is loaded with an impermissibly high tensile stress.
The invention is based on the object of indicating a way in which an elongate product can be unwound satisfactorily in a straightforward manner from its storage device. According to the invention, in a method of the type mentioned at the beginning, this object is achieved in that the elongate product is transported away in the axial direction from the storage device in such a way that at least one loop is formed at at least one longitudinal point on its longitudinal outward transport path, that changes in the geometric shape of the loop are registered, and that these changes are used to derive at least one control criterion for the outward transport movement of the elongate product.
The fact that at least one loop is formed for the elongate product along its longitudinal haul-off path, after it has been transported away from its storage device, and changes in the geometric shape of this loop are registered and used to derive at least one control criterion for the outward transport movement of the elongate product means that the elongate product can be unwound from its storage device satisfactorily under a large number of practical conditions.
This principle according to the invention is preferably suitable for unwinding telecommunication cable elements, in particular optical transmission elements, preferably optical waveguide cable, from supply coils or supply plates.
The invention further relates to an apparatus for unwinding an elongate product from its storage device, on which the product is stored with a large number of turns, which is characterized in that outward transport means for transporting the elongate product away from its storage device in the axial direction are provided in such a way that at least one loop of the product can be formed at at least one longitudinal point in its longitudinal outward transport path, in that a measuring device for registering changes in the geometric shape of the loop is provided, and in that this measuring device is assigned a control device which uses these changes to derive at least one control criterion for the outward transport movement of the elongate product.